Set of bristles for a toothbrush



FIG. 1 is a perspective view of my ornamental design for a set of bristles for a toothbrush;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a side elevational view thereof, the opposite side being a mirror image; and,

FIG. 5 is an end view thereof, the opposite side being a mirror image.

The structure shown in phantom or broken lines in the FIGs. forms no part of the claimed design and is included only to illustrate an environment. 

The ornamental design of a set of bristles for a toothbrush, as shown and described. 